Channel 1, 2, 3 and 4 - PSK31 Deluxe allows from 1 to 4 specific channels (signals) to be selected for decoding. The one currently selected becomes highlighted - Channel 1 in this image. The Channel 1, 2, 3 and 4 options, or their corresponding toolbar buttons, allow swapping between the signals with a mouse click. The selected channel becomes the current operating channel.